*HELP* N2 and N2 Plus Calibration Issues

cowtownam
Posts: 3
Joined: Fri Oct 25, 2019 1:10 am

*HELP* N2 and N2 Plus Calibration Issues

Postby cowtownam » Sun Dec 01, 2019 2:26 pm

Hello,

I am a small business owner / model maker who recently got rid of my Lulzbot Taz 6's and "upgraded" to three Raise3D's -- or so I thought!!! I have an N2 and two (2) N2 Plus' and they typically are running 24/7 making models for my customers. As of today, 0 of the 3 are successfully printing models.

I had the first N2 Plus for over a year and printed anything/everything with little to no problems -- models of all shapes & sizes and complexity. I've utilized the entire 24" int the Z axis to make some amazing looking parts so I know I didn't just get some "bad printer off the Raise3D production line" like I see some people complain about on here. The N2 and 2nd N2 Plus I've had since August and same situation.

All of the sudden all THREE printers decided to start going haywire and it would appear that the bed is not level. I used the .02mm feeler gauge to perform the z-calibration on all 3 machines. Each machine's calibration is different but as I tram across the build plates it is clear that the build plates are NOT planar to the gantry system, nor are they level. I am no fool, I understand I have a desktop machine here and they are not perfect, material is not infinitely stiff, and that the extruder head will sag a little bit, perhaps the rods may have some sag. But not this bad?? Why did my printers work so amazing prior to this? Perhaps I am overlooking something so simple and easy because I've been staring at the problem so long..

All 3 of my printers have the single extruder BondTech upgrade so i've eliminated a lot of the weight pushing down on that gantry system. All 3 printers were printing phenomenal parts prior to them all taking a crap. For all of them to screw up all simultaneously and no prints able to stick to the bed is odd to me. No sudden changes in mechanical configuration to the machines were made nor did I stray away from the print parameters/profiles I've been using for the past year.

Please see attached pics from my N2 Plus "Thor" -- all machines are showing the same side affects: raft sometimes has lines that simply won't stick to the bed, extruder head drags across top of the model even though the z-adjustment was done. Sometimes I can get a really nice raft to lay down then the very first layer of the model the extruder head is literally digging into the top of the raft while trying to extrude it seems. There's other areas in the model where it seems the extruder head is simply too far away from the bed whereas it's perfectly distanced in other areas of the bed it trams over. Which leads me to believe my bed is out of calibration.

Any help would be greatly appreciated it.. I guess I've been kind of spoiled the past 6 months getting such great prints perhaps I failed to maintain something mechanically on the machine. I really DO NOT want to touch the bed leveling point system -- Raise3D advertises a "out of the box" factory calibration and, up until now, they held up that end of the bargain. Does this bed eventually go out of calibration and users are forced to attempt to calibrate the bed via tramming & using a dial? I was told that the raft was the great equalizer on these machines which helps to overcome the inherently unlevel bed that comes with these machines.

Thanks,

Ethan
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Vicky@Raise3D
Posts: 6737
Joined: Fri Mar 25, 2016 3:54 am

Re: *HELP* N2 and N2 Plus Calibration Issues

Postby Vicky@Raise3D » Tue Dec 03, 2019 1:38 am

Would you like to print a full size cube with only first layer and see how it turns out to be?

cowtownam
Posts: 3
Joined: Fri Oct 25, 2019 1:10 am

Re: *HELP* N2 and N2 Plus Calibration Issues

Postby cowtownam » Thu Dec 12, 2019 2:36 pm

Vicky -- here's an update. It is clear to me that my "factory calibration" has now gone out due to 3 years of thermal expansion/contraction and machine vibration. These machines were all manufactured in 2016 according to the stickers on the back. I bought all of them used from the original owner. I cannot attest to how well this individual maintained the machines or not.

Based on prints continuing to fail over and over again + previous posts on the forum here I decided to loosen the heated bed entirely and re-tram/calibrate the bed across all 13 points based on JetGuy's youtube video (https://www.youtube.com/watch?v=Du8OdPosrMo) using a dial indicator.

I successfully have re-leveled all 3 beds and have been running prints on them (which look great), HOWEVER, they keep going back out of calibration almost every other print. I then have to put the dial indicator back on and make minor adjustments using the grub screws below the aluminum plate to get it back into proper calibration then can run another print. I haven't really run any super long prints since doing this (say 6-8 hours or less) so there is no telling what would happen with a longer print -- if they bed would stay in calibration through the entirety of the print or not.

While loosening up the original "factory calibrated" beds, I noticed it appeared that some type of Loctite was used while inserting these grub screws and doing the factory calibration. Can you tell me exactly what type of loctite was used so I can go purchase and reapply / recalibrate? I believe unless I re-apply said Loctite the machines will only continue to go out of calibration and I repeat this crazy cycle...

All rods have been cleaned + regreased using the OEM recommended SuperLube PTFE lubricant. All screws, bolts, etc. have been gone over more than 3 times and ensured tightness. All axis couplers have been examined for any wear/tear, shearing or damage. None is present. No replacement of couplers required at this time - and yes I did flip each machine on its side and inspected the underside Z belt + coupler and motor.

The belt tension seems fine (not too loose, not too tight) on both N2+ machines. On my N2 machine, it appear the belts MAY be tighter. The extruder head is much harder to move around by hand when compared to the other 2 machines. I took the N2 lid off while inspecting the couplers, rods, belts and all screws. Everything looks aligned and all screws were tightened. I know the human eye is not perfect but is there some better instruction out there for ensuring rod alignment? The instructions on the website are lackluster and not very detailed.

How does one measure belt tension? Is there a tool I can purchase online to achieve this? What is the proper OEM belt tension that should be applied to these machines? Are there step by step instructions that shows a user how to adjust belt tension?

Also on the N2 -- I keep hearing an awful squeaking/scratching noise that SEEMS to be coming from the extruder head carriage but it's hard to tell. Knowing that I have checked all of the couplers on this machine and there are no damaged/sheared couplers, these are not the problem. Could it be that the linear motion bearing inside the extruder chassis have worn out and need to be replaced? (LM8LUU bearings) --- the printer is printing right next to me as I type this. The print quality is fine and I am hoping to see this print complete here in the next 10 hours. The only issue is this awful noise.. I will try to record a video and post to youtube so you can hear it.

Lastly, knowing that all 3 of my machines are 3-4 years old now being made in 2016, what should I consider totally replacing from a mechanical hardware perspective? Is it a good idea to just replace all the couplers? The rods? The belts? I have been printing on these machines every day non stop for hundreds of hours. They've seen a lot of "wear and tear" so I want to make sure they are getting the love they need.

Thanks,

Cowtown AM

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Vicky@Raise3D
Posts: 6737
Joined: Fri Mar 25, 2016 3:54 am

Re: *HELP* N2 and N2 Plus Calibration Issues

Postby Vicky@Raise3D » Fri Dec 13, 2019 11:28 pm

Do you mean this document? We usually loosen the grub scews of pulleys and move the extruder head around to let the pulleys align to the position during moving.
https://support.raise3d.com/N2-N2-Plus/ ... 3-680.html

About belt, please make sure the four direction are under similar tension. Attached two belt installation guides for your reference.
https://support.raise3d.com/Pro2-Series ... 4-576.html
https://support.raise3d.com/Pro2-Series ... 4-684.html

We have heard some linear bearing having weird noise cases and being solved by replacing extruder head. You can take it into consideration.
If your printer doesn't have layer shifting, binding or out of shape print result by now, replacing machnical parts doesn't need to be considered at the moment.

If you are not sure of the condition of your printer, feel free to share the videos with our technicians at http://help.raise3d.com to help you confirm.

cowtownam
Posts: 3
Joined: Fri Oct 25, 2019 1:10 am

Re: *HELP* N2 and N2 Plus Calibration Issues

Postby cowtownam » Mon Dec 16, 2019 9:14 pm

Update:

I implemented the bed modification designed by TobyCWood (https://www.thingiverse.com/thing:1409412) & used some of gpvillamil's remix (https://www.thingiverse.com/thing:1992664) on one of my N2+ machines -- this is a game changer. I am now able to tram/level the bed in less than 60 seconds by moving the extruder head around freely and using the .02 feeler gauge to make minor quick turn adjustments on the wing nuts below the bed. It's a breeze to now switch between materials and different build plate surfaces in an efficient manner. No more messing with the z-offset switch. The bed is perfectly level across all 12 inches of the bed if you take your time and do it right when installing. The first layer quality is like when I first got the machine.

If you desire to print on straight glass without a raft, I highly recommend this modification. It's relatively cheap to implement and requires a couple of printed parts -- I did the spacers and wing nuts in ABS for it's good thermal/mechanical properties in this particular application. The stronger springs and longer flat head screws make this operation a breeze. My machines already had the v2 heat beds with the insulation so I opted for the oxidized washers for longer life and did not have to mess with any kapton tape application or printed washers.

I successfully ran 10 calibration prints covering the maximum build plate size with no layer adhesion issues or bed level issues. I am now on my 3rd 10+ hour long print. The first 2 were a success and very nice quality. If this third complex model finishes with no issues I am going to proceed with the modification on the other N2+ and my N2.

I have not had the opportunity to revisit the N2 machine (the one with what appears/sounds to be binding issues) but will revisit this when I get the chance. For now, I am just happy to be printing again.

I would expect the next R3D machine to be released to have auto bed leveling with sensors integrated into the system -- similar to Ultimaker's S5 active bed leveling which has been extremely impressive to experience.

Thanks for the help Vicky. I will report back when I get a chance to take a look at the x/y rods on the N2.


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